The present invention relates to photographic processors, as well as a filter assembly for a photographic processor which includes a level sensing probe.
Conventional photographic processors are typically provided with a filter assembly disposed in a recirculation system. The filter assembly is effective for filtering particles in a processing solution that is being re-circulated. A conventional filter assembly includes an inlet port for receiving processing solution from a processing tank for recirculation, and an outlet port for delivering the filtered solution back to the processing tank. The conventional filter assembly further includes a heating element for heating the processing solution while in the filter assembly. The heating element is usually connected to sensors that measure the temperature either within a filter housing of the filter assembly or at some other point in the processing system (see for example, U.S. Pat. Nos. 5,701,540 and 5,753,111).
A drawback with conventional filter assemblies is that the heating element is responsive to a temperature within the filter housing as opposed to a level of processing solution within the filter housing. Therefore, the heating element in a conventional filter assembly remains in an activated or on state regardless of the level of solution in the filter housing. This causes a problem in that components of the filter housing could overheat when the solution level within the filter housing falls below an acceptable level while the heating element is still on. This could adversely effect the operation of the filter assembly and its associated processing equipment.
An object of the present invention is to provide for a photographic processor having a filter assembly that includes a filter housing which overcomes the above-mentioned drawbacks. More specifically, the present invention provides for a filter housing having a level sensing probe which is designed to assure that the level of processing solution in the filter housing is at a proper height to prevent an overheating of components of the filter housing.
With the system and method of the present invention, if the processing solution level within the filter housing drops below an acceptable level, for whatever reason, the heating element is automatically shut off. This will prevent any damage to the filter housing or components of the filter assembly due to overheating when the solution drops below an acceptable level, and when the solution pump is recirculating processing solution.
The present invention accordingly relates to a processing apparatus for processing photographic material. The apparatus comprises a processor, a circulation system for circulating processing solution to and from the processor, a filter assembly provided in the circulation system, with the filter assembly comprising a filter housing having a heating element therein; a level sensing probe provided on the filter housing; and a controller arrangement operationally associated with the level sensing probe and the heating element. The controller arrangement is adapted to turn off the heating element when the processing solution in the filter housing falls below a level on the filter housing as defined by the level sensing probe.
The present invention also relates to a filter assembly for a photographic processor. The filter assembly comprises a filter housing adapted to hold a processing solution; a heating element for heating processing solution in the filter housing; and a level sensing probe provided at a predetermined level on the filter housing which approximately defines an acceptable minimum level of processing solution in the filter housing. The level sensing probe is adapted to provide a signal to a controller arrangement to shut off the heating element when a level of processing solution in the filter housing falls below the predetermined level.
The present invention further relates to a method of processing photosensitive material. The method comprises processing photosensitive material in a processor having a processing solution therein; circulating the processing solution from the processor to a filter housing; heating the processing solution in the filter housing; and stopping the heating of the processing solution in the filter housing when a level of processing solution in the filter housing falls below a predetermined level.
The present invention further relates to a processing apparatus for processing photographic material which comprises a processor; a filter assembly adapted to provide filtered processing solution to the processor, with the filter assembly comprising a filter housing have a heating element therein; a level sensing probe provided on the filter housing; and a controller arrangement operationally associated with the level sensing probe and the heating element. The controller arrangement is adapted to turn off the heating element when the processing solution in the filter housing falls below a level on the filter housing as defined by the level sensing probe.
The present invention further relates to a method of processing photosensitive material which comprises supplying a processing solution to a filter housing; heating the processing solution while in the filter housing; supplying the processing solution from the filter housing to a processor for processing photosensitive material; and stopping the heating of the processing solution in the filter housing when a level of the processing solution in the filter housing falls below a predetermined level.